Polyisocyanate mixtures

Patent metadata

Field	Value
Publication number	US-9458318-B2
Application number	US-201113811088-A
Country	US
Kind code	B2
Filing date	Jul 15, 2011
Priority date	Jul 20, 2010
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

The invention relates to novel solvent-free, monomer-depleted polyisocyanate mixtures, and to the use thereof for producing light-resistant and weather-resistant polyurethane bodies with high optical refraction and low optical dispersion.

First claim

The invention claimed is:

1. A solvent-free polyisocyanate mixture A) comprising:
5 to 95 wt.% based on a total wt. of polyisocyanate mixture A) of at least one polyisocyanate a-1), said at least one polyisocyanate a-1) being based on hexamethylene diisocyanate, said at least one polyisocyanate a-1) having an NCO content of from 16 to 24 wt.% based on a total wt. of polyisocyanate a-1), and said at least one polyisocyanate a-1) exhibiting a viscosity at 23° C. of from 70 to 12,000 mPas; and
95 to 5 wt.% based on a total wt. of polyisocyanate mixture A) of at least one polyisocyanate a-2), said at least one polyisocyanate a-2) being based on araliphatic diisocyanate, said at least one polyisocyanate a-2) having an NCO content of from 10 to 22 wt.% based on a total wt. of polyisocyanate a-2), said at least one polyisocyanate a-2) having a monomer araliphatic diisocyanate content of less than 1.0 wt.% based on a total wt. of polyisocyanate a-2), and said at least one polyisocyanate a-2) either being a solid at 23° C. or exhibiting a viscosity at 23° C. of more than 150,000 mPas;
said at least one polyisocyanate a-1) being different from said at least one polyisocyanate a-2); and
said polyisocyanate mixture A) having a total content of isocyanate groups of from 11 to 23 wt.% based on a total wt. of polyisocyanate mixture A), said polyisocyanate mixture A) having a mean isocyanate functionality of at least 2.3, and said polyisocyanate mixture A) having a monomeric diisocyanate content of less than 1 wt. % based on a total wt. of polyisocyanate mixture A).

2. Polyisocyanate mixtures A) according to claim 1 , wherein the polyisocyanates of component a-1) have a viscosity at 23° C. of from 70 to 1600 mPas and a content of isocyanate groups of from 18 to 24 wt.%.

3. Polyisocyanate mixtures A) according to claim 1 , wherein the polyisocyanates of component a-2) are those with a uretdione, allophanate, isocyanurate, iminooxadiazinedione and/or biuret structure.

4. Polyisocyanate mixtures A) according to claim 3 , wherein the polyisocyanates of component a-2) are those based on m-xylylene diisocyanate (m-XDI), p-xylylene diisocyanate (p-XDI) and/or m-tetramethylxylylene diisocyanate (m-TMXDI) having a content of isocyanate groups of from 11 to 21.5 wt.% and a content of monomeric diisocyanates of less than 0.8%.

5. Polyisocyanate mixtures A) according to claim 3 , wherein the polyisocyanates of component a-2) are those based on m-xylylene diisocyanate (m-XDI) having a content of isocyanate groups of from 15 to 21 wt.% and a content of monomeric m-XDI of less than 0.5%.

6. Process for the production of light-fast polyurethane compositions comprising solvent-free reacting of
A) the solvent-free polyisocyanate mixtures according to claim 1 with
B) reactants that are reactive towards isocyanate groups and have a mean functionality of from 2.0 to 6.0, optionally with the concomitant use of
C) further auxiliary substances and additives,
while maintaining an equivalent ratio of isocyanate groups to isocyanate-reactive groups of from 0.5:1 to 2.0:1.

7. Process according to claim 6 , wherein the reactants B) that are reactive towards isocyanate groups are hydroxy-, amino- and/or mercapto-functional compounds having a mean molecular weight of from 60 to 12,000.

8. Process according to claim 6 , wherein there are used as the reactants B) that are reactive towards isocyanate groups polyether polyols, polyester polyols, polycarbonate polyols and/or amino polyethers having a mean molecular weight of from 106 to 12,000, polythioether thiols, polyester thiols, sulfur-containing hydroxy compounds and/or low molecular weight hydroxy- and/or amino-functional components having a mean molecular weight of from 60 to 500.

9. Process according to claim 6 , wherein there are used as auxiliary substances and additives catalysts, UV stabilisers, antioxidants and/or mould release agents.

10. Process according to claim 6 , wherein the reacting of the reactants is carried out at a temperature of up to 180° C. and a pressure of up to 300 bar.

Assignees

• Greszta-Franz Dorota
• Laas Hans-Josef
• Halpaap Reinhard
• Mager Dieter
• Meier-Westhues Hans-Ulrich
• Covestro Deutschland Ag

Inventors

• Greszta-Franz Dorota
• Laas Hans-Josef
• Halpaap Reinhard
• Mager Dieter
• Meier-Westhues Hans-Ulrich

Classifications

• C08G18/7831

  containing biuret groups · CPC title

• C08L75/04 Primary

  Polyurethanes · CPC title

• C08G18/4211

  derived from aromatic dicarboxylic acids and dialcohols · CPC title

• C08G18/3876 Primary

  containing mercapto groups · CPC title

• C08G18/798

  containing urethdione groups · CPC title